Filter medium or other article of manufacture.



E. J. SWEETLAND. FILTER MED llllllllllll RTGL FFFFFFFFFFFFF E.

APPLICATIO'? FILED MAY25', E914.

lM??9 Patented July 2o, 1915.

2 EEEEEEEEEEEE I.

QFHG. FGE. FGMS.

mfp a FEGL. Fggh' a oEEIcE.

Enlv-Efsirjr'.l swEETLAND, or MoN'rcLAIE., NEW JERSEY.

FILTER MEDIUM OR OTHER ARTICLE F MANUFACTUR.

of which the following is a specification.

My invention relates particularly to a filter medium comprising a wovenfabric of fine metallic wires. Hitherto the filter medium. most used hasbeen cloth, and for many purposes this is entirety satisfactory.However, when the substance to be filtered contains van agent which isdestructive of cloth, such for instance as strong alkalis, the

ycloth filter medium is rapidly destroyed. destroyed cloth represents-To replace the not only a considerable expenditure of time and financialloss, due to the period during which the filter is thrown out ofservice, but also a large expense for new cloth.

The chief object of my present invention is to provide a filter mediumwhich may be used to replace cloth and which will be composed ofmaterial thatl yis not attacked by the agents which destroy the cloth,butI realize that my improved fabric may be advantageously used for anumber of other purposes in the arts so that, except as specificallysetv forth, I do the claims to a filter fabric. For instance, when wateris forced through the fabric under pressure, it is broken upon into afine spray having characteristics different from those of any spray ofwhich I am aware. rllhe fabric permits a relatively large volume ofwater, or other fluid, to pass through it, but at the same time' breaksit up into an exceedingly fine spray which is useful in wateringvegetation, in shower baths and in many other situations, as will beobvious. This is only one additional use for my improved fabric, and Ido not deem it necessary to set forth others in detail.

In my improved filter structure I provide a filter medium which iscomposed of interwoven metallic wires, which are preferably o f anexceedingly small diameter. I am aware that in the filtrationv ofcertain substances, the use of fine wire netting or screen has hithertobeen proposed, but such netting or screen acts as a strainer rather thanasa truefilter medium, whereas my' improved fabric will lter a slimysludge and obtain Specification of Letters Patent. l

not desire to limit" Patented July 20, 1915.`

VApplication filed May 25, 1914. Serial N o. 840,731.

therefrom a filtrate which is crystal clear. Furthermore,

that their commercial use ispractically prohibited under normalconditions of operation and their expense is comparatively great. On theother hand my improved filter fabric is rugged in its texture and itscost is not exorbitant.

Another great advantage of my improved fabric over ordinary screen isthe resistance which it offers to the passage of air through it. This isof importance in filtration, since it is common to dislodge the filtercake from the filter medium by introducing compressed air into thefilter leaf. If the'filter medium is wire screen, a small piece of thefilter cake will break away first and the compressed air will rush outthrough the opening thus formed in the cake, so that the remainder ofthe cake is not dislodged. My improved fabric offers such a resistanceto the passage of the air that the breaking away of a small piece of thecake in the manner above described will not release the air pressure toany considerable extent and the remainder of the cake will, therefore,be entirely dislodged.

In. the accompanying drawings which form a part of this specification,Figure 1 is a plan view of one `form of my improved fabric; Fig. 2 is atransverse sectional. view of the structure of Fig. 1; Fig. 3 is a plan'view of the structure of Fig. 1 after it has been flattened underpressure, as by rolling; Fig. 4 is a View similar to Fig. 1 showing amodified form of construction; Fig. 5 is a transverse sectional View ofthe structure of Fig. 4; Fig. 6 is an elevation of la filter leaf inwhich my improved fabric is utilized; Fig. 7 is a transverse sectionalview on line VII- VII of Fig. 6. Fig. 8 is a diagrammatic view similarto Fig.. 1, but showing a twill fabric. Fig. 9 is a diagramf maticsectional view of the structure of Fig. 8. Fig. 10 is a diagrammaticview similar to Fig. 3 showing the twill fabric after it has beenrolled. Fig. 11 is a diagrammatic the wires may be these fine wirescreens previously used are so delicate 1n their texture wires may beconveniently aggregated while lying parallel to each other by the use ofsoap, wax, or other adhesive, which will cause the wires composing abundle to cling together during the process of weaving, but` which maybe eliminated after the weaving of the filter structure is completed.

In using the word bundle in this specification, I intend it to beconsidered simply as a convenient term for describing a plurality ofwires forming a strand, and do not desire to limit it to a structure inwhich the wires are secured to each other, either by `twisting or in anyother way, such as the use of soap, wax or other adhesive.

As an example of the dimensions which are found convenient for certainfiltration purposes, but without limiting myself in any way to theirspecific use, I may state that a filter medium may be advantageouslywoven in which each warp and weft thread is composed of sixty (60)strands of wire 0.003 of an inch in diameter. When these strands areclosely interwoven a fabric will be formed which has nearly ,one millionin- .terstices to the square inch. 'Ihe finest screen or netting ofwhich I am aware is manufactured with about 200 wires each way to theinch, thus giving about 40,000 interstices. It will thus be seen that inaddition to certain other advantages, the fabric as described above has25 times as many interstices per unit of area. In some instances such anextremely fine fabric is not needed, and by way of example it may bestated that a filter cloth composed of bundles containing as few as fivefilamental wires each is satisfactory for many purposes. Wires of thisgeneral nature may conveniently be termed filamental wires and this termfor convenience is used in this specification and claims. N

After the fabric is vroven I find that it is extremely advantageous tosubject it to pressure, in order to flatten out the strands and cause amore homogeneous texture. i 'Ihe general appearance of the fabricsubsequent to fiattening, which is best obtained by rolling betweenpressure rolls, the distance between which may be adjusted with greatprecision, is shown in Fig. 3 of the drawings. A very great advantagewhich inheres in -the process of rolling is the fact that such rollinggives to the fabric a smooth glass-like surface to which the filter cakewill not strongly adhere. The filter cake may, therefore, bereadily-released from the surface of the filter fabric either byreversing the fiow in the manner fully described in my Patent No.1,083,305, dated January 6, 1914 or in any other of the ways well knownin theart of filtration.y

In place' of constructing both the warp and the weft threads of aplurality or bundle of wires, I find that a very satisfactory filter,lfabric may be obtainedby making one set of threads, as for instance thewarp threads, single wires of a diameter which will approximate thediameter of the bundle of aggregated wires used for the other set ofthreads. 'Ihis construction is illustrated in Fig. 4, in which thenumeral 4 designates the warp threads composed of single wires which areinterwoven with the weft threads 5. composed of bundles of wire, asabove. After weaving, this fabric is preferably subjected to the sameoperation of rolling or other compression to aggregate its individualelements more homogeneously.

- In Figs. 6 and 7 I have shown a filter leaf composed of an outer frame6 of channel section having' inwardly inturned legs 7 and 8. A nipple 9is inserted in the frame at one point and has its inner end split toform the legs 10 and 11 which straddle a drainage member 12 which maypreferably be constructedof coarse screen. On either side of the member12 is a layer 13 of my improved filter fabric constructed in either ofthe ways already described. The edges of these layers. are retainedbetween the legs 7 and 8 of the channel frame, and sealing lips liquidto be filteredl between the edge of the leg and the edge of the filtermedium.

Such a filter leaf as I have above described may be applied to the typeof filter shown and described in detail in my Patent No. 1,083,305,datedV January 6, 1914. rIhe course of the filtrate, as will be obvious,will be through the filter fabric 13, thence through the space formedbetween the two layers of fabric by the coarse screen 12. rIhe clearfiltrate passes out through the nipple 9 to the outlet manifold, whichis not shown. The application of my improved fabric to the type offilter-leaf shown in Figs. 6 and 7 is of course merely by way ofillustration and I appreciate that the fabric may in many instances beadvantageously used to replace existing' filter media in otherwell-known types of filters.

While I have shown in Figs. 1 to 5 of the drawings the so-calledbasket-weave, it is obvious that other forms of weaving may beadvantageously employed, such for instance as that forming a twillfabric.

In Figs. 8, 9, 10 and 11 I have illustrated in a diagrammatic way, theapplication of each leg for preventing the passage of the my inventionto a twill fabric which, for certain purposes, has the advantage offorming ticular improvements in Adesire to be limited A particularly ofFigs. 8 and 9, is diagrammatic and on a greatly enlarged scale. Inactual construction, the parts are so tightly woven that the intersticesappearing in Figs. 8 and 9 between adjacent strands are to a greatextent done away with even before the fabric is rolled.

I have shown in Figs. 8 to 11, inclusive, what is known as a two leaftwill, but itsy will be obvious that other forms of wellknown twillfabrics may be employed. Furthermore, I have illustrated and describedonly certain specific embodiments of my invention, but I realize that itis susceptible of wide application and I do not to the preciseconstruction set forth.-

I do not claim in this application the parl the method of making thefabric described, since this forms the subject matterof my co-pendingdivisional application, Serial No. 33,156.. Having thus described myinvention, I

e claim:

1. A filter medium comprising a closely woven fabric, the warp threadsofwhich are composed of bundles of filamental metallic wires.

2. A 1ilter medium comprising a closely woven fabric, the warp threadsof which are composed of twisted bundles of flamental metal ic wires.

3. A filter medium comprising a closely woven fabric, the weft threadsof which are composed of bundles of iilamental metallic wires.

4. A lilter medium comprising a closely woven fa-bric, the weft threadsof which are 1 composed of twisted bundles of filamental metallic wires.

5. A filter medium comprising a woven fabric having one set of threadscomposed of bundles of metallic. wires, said fabric being flattenedunder pressure.

, 6. A filter medium comprising a woven fabric, one set `of threads ofwhich is composed of twisted bundles of metallic wires, said fabricbeing iiattened under pressure.

7. A filter medium comprising a woven fabric, one set of threads ofwhich is composed of bundles of metallic Wires, said fabric being rolledunder pressure after vweaving to flatten the same.

8. A filter medium comprising a woven fabric, one set of threads ofwhich is composed of twisted bundles of metallic wires, said fabricbeing elongated under pressure in one. direction more than another, asby rolling.

9. A filter medium comprising a closely woven fabric, both the warp andthe weft 'of -iilamental metallic wires.

woven fabric, both the warp and the weft ofwhich are composed of twistedbundles of 11. A filter medium comprising "a woven fabric, both sets ofthreads of which `are composed of bundles of metallic wires, said fabricbeing attened under pressure.

12. A filter medium comprising a woven fabric, both sets of threads ofwhich are composed of twisted bundles. of metallic wires, said fabricbeing flattened under pressure.

13. An article of manufacture comprising a woven fabric, one set ofthreads of which is composed of said fabric being iattened underpressure.

14. An article of manufacture comprising a woven fabric, one set ofthreads of which is composed of twisted bundles of metallic wires, saidfabric being attened under pressure.

15. An article of manufacture comprising a woven fabric one set ofthreads of which is composed of bundles said fabric being elongatedunder pressure in one direction more than another, after weaving, as byrolling.

16. An article of manufacture comprising a woven fabric, one set ofthreads of which wires, said fabric lbeing elongated under pressure inone direction more than another,

after weaving, as by rolling.

17. An article of manufacture comprising a closely woven fabricpresenting substantally no interstices, both the warp and the weft ofwhich are composed of bundles of metallic wires.

18. An article of manufacture comprising a closely woven fabric.presenting substan` tally no interstices, both the warp and the weft ofwhich are composed of twisted bundles of metallic wires'.

19. An article of manufacture comprising a woven fabric, both the warpand the weft of which arecomposed of bundles of metalbundles of metallicwires,

of metallic wires,

is composed of twisted bundles of metallic lic wires, said fabric beingflattened under pressure. Y

20. An article of manufacture comprising a woven fabric, the warp andthe weft of which are composed of twisted bundles of metallic wires,said 'fabric being fiattened under pressure. p ERNEST J. SWEETLAND.Witnesses:`

GERALD E. TERWILIJGEn, W. R. WARNER.4

'Cerreeten in Letters Patent-Ne.. 1,147,279

lt is hereby certified thatin Letters Patent No. 1,147,279, granted July20,

1915, upon the application of Ernest J. Sweetland, of Montclair, NewJersey, for en improvement in Filter Mediums or @ther Articles ofManufacture," an error a,p'

peers in the printed specification requiring correction as follows: Page1, line 34,

for the Word upon read up; and that the seid Letters Patent should beread with this correction therein that the seme may conform to therecord ofy the oase in the Patent Oofa.

Signed and sealed this 21st day of December, A. D., 191.5.

[SEAL] J. T. NEWTN,

C1.' 139-9 Acting Commissioner of Patents.

